Christie S. Warren, Islamic Criminal Law, Oxford University Press, Qisas
sunnah.com
"I have been ordered (by Allah) to fight against the people until they testify that none has the right to be worshipped but Allah and that Muhammad is Allah's Messenger, and offer the prayers perfectly and give the obligatory charity, so if they perform that, then they save their lives and property from me except for Islamic laws and then their reckoning (accounts) will be done by Allah."https://sunnah.com/bukhari/2/18